Haw. Rev. Stat. § 481M-6: Early termination.

The lessee shall have the right to acquire ownership of the property at any time after the initial payment by tendering to the lessor all past due payments and fees and an amount equal to the cash price stated in the lease-purchase agreement multiplied by a fraction that has as its numerator the number of periodic payments remaining under the agreement and that has as its denominator the total number of periodic payments.